This invention relates to molded plastic containers, bottles, and the like having integrally molded multi-element closures, and to integral tamper indicating systems for such containers.
Plastic containers that are currently available require two separate components. The two main components of the container are the container body, which defines one or more compartments, and a cap or closure which is adapted for mounting on the container body for sealing the compartment or compartments. Typically, the container body has a restricted neck portion and accordingly is produced by an extrusion or injection blow molding operation. Manufacturing containers by extrusion blow molding generally offers the advantage that undercuts are easily formed. Extrusion blow molding has the disadvantage that no integral solid components can be formed concurrently, but hollow shapes such as a handle can be formed by the volume of the container. Therefore, presently the closure for the container is produced separately by an injection molding process and is assembled to the container body after the container has been first filled with the required contents. Injection blow molding offers the advantage of being able to form integral solid components, for example, a solid handle. An example of this is illustrated in French Patent no. 1,192,475 where an integral solid handle is formed as part of an injection blow molded bottle. However, each separate component requires its own set of tooling, manufacturing infrastructure and inventory control.
In many applications, the neck or container opening is too large to act as a restricting orifice. For such applications, a third or intermediate component that includes a small orifice or multiple orifices, is provided, to aid in the dispensing of flowable material. Pouring through a small restricting orifice aids in metering out of the contents and limits the amount of spillage if the container is tipped over. The intermediate or orifice component and closure are sometimes combined, forming a one-piece closure. One example of such a combination of closure/orifice is the dispensing closures used for example for shampoo bottles and the like.
Often, the components of the container are manufactured from plastic in separate operations in separate tooling in separate factories, after which assembly of the separate components is required, prior to the container being filled with the necessary contents. This requires transport costs and automated sorting and assembly of the closure to the body on the filling line. Consequently, this method of manufacture is characterized by compounded relatively high material, tooling and handling costs, as well as increased costs for assembly. Moreover, producing the body of the container and the container closure from different materials complicates recycling of the containers. Such container and closure packages would be more economically and environmentally friendly if they could be produced from the same material in one manufacturing operation in one factory.
A further consideration is that tamper indication is becoming more of a necessity than a luxury. As the cases of malicious tampering increase, the public need and expect to be protected. Tamper evident containers are now becoming a prerequisite of all types of substances, for example, foods, pharmaceuticals, toiletries and other domestic and industrial products.
Many methods of tamper evidence are employed. Most methods require separate tooling, additional manufacturing infrastructure, transportation, inventory control and automated assembly. Two common forms of tamper evidence include the use of a plastic sleeve that is shrunk onto the container, for example a jar of honey, and a plastic circumferential tear tab that is formed integrally with a pivotal or removable cap assembled, for example, a pill container. Some of the disadvantages of the sleeve concept are that separate tooling is required to manufacture the sleeve and that production machinery is required for assembly. In addition, the technology is easily within the grasp of an individual desiring to compromise the tamper evident system.